Use of Inertial Sensors for Determining Kinematic Characteristics of Infant Leg Movement Motor Rehabilitation

Inertial sensor data were collected from 12 infants with typical development for a period of 8-13 hours per day. There were 2 months between visits and a total of 3 visits per infant. An inertial sensor was attached to each leg, recording simultaneously accelerometer and gyroscope measurements at 20Hz. In previous work, we developed and validated a threshold-based algorithm where each pause or change of direction of the limb is counted as a discrete movement. Here we determined the duration, average acceleration, and peak acceleration of each movement. The duration of each movement was computed by counting the number of samples when the acceleration magnitude was above baseline until it crossed the baseline for a second time. Consequently, acceleration magnitude was obtained for each of these samples and average acceleration and peak acceleration of each movement was calculated.